
Pistons & Pivots
Pistons and Pivots : James Cowan's Ex-Military Ambulance & Cannondale Jekyll
Pistons and Pivots features cool vehicles with character, and a little about their owners and the bikes they ride.
If you've got a vehicle and bike that fit the series, we'd love to help you share them with a wider audience, and you can take a crack at winning some prizing from Maxxis (tires are hard to come by in the days of Covid, so Maxxis has kindly offered to pay for two trail association memberships - one for you and a friend or two for you!).
You can enter in one of two ways:
- Send photos and articles to [email protected]. Make sure to include 'Pistons and Pivots' in the subject line.
- Or simply post a few vehicle and bike photos and details to Instagram and use the hashtags #pistonsandpivots and #nsmb.
We'll pick a few winning submission and feature them on the site, and the person that submitted it will earn a membership to their local trail association as well as one other (for another trail association or to share with a friend) courtesy of Maxxis.

1985 Chevy Military Ambulance

Bike for scale here, this thing is big
Deniz Merdano - Hi James, Please introduce yourself a little.
I’m a couple years younger than my truck and work as a mechanical engineer here in British Columbia. My wife and I moved from Ottawa to North Vancouver in 2018, a move back home for her. As a lifelong mountain biker who grew up watching Kranked 3 – Ride Against the Machine on repeat, our move to B.C. was a dream come true for me. Having spent the last four years exploring the trails here on the North Shore, the Sunshine Coast, on Vancouver Island, and up the Sea-to-Sky corridor, I feel like I’ve barely scratched the surface.
I have my dad to thank for my interest in mountain biking. He’s been riding, racing and bikepacking for decades and always made the time to take my friends and me out on the trails as kids.
Well the reason everybody is here today... the 1985 Military Ambulance (does it have an official name?)
This bucket of bolts is a 1986 CUCV M1010, retired Canadian military ambulance. Based on the limited information I have on its past life, I’d guess that the truck spent some time as an airfield ambulance at CFB Bagotville. We’ve officially named it ‘Rolling Thunder’, but often just refer to it as the Campulance.
The M1010 is basically an up-fitted 80’s Chevrolet K30 chassis cab truck with a big aluminum box on the back. There were several different CUCV (Commercial Utility Cargo Vehicle) variants. Some had PTO driven generators and air compressors, command shelters or fire fighting equipment, but they were all based on ‘off the shelf’ GM trucks.
Rolling Thunder is powered by a naturally aspirated 6.2L V8 Detroit Diesel, paired to a TH400 3 speed automatic transmission (Turbo Hydra-Matic, dude). It has leaf springs and solid axles front and rear with a Dana 60 up front and a 14-bolt full floater rear axle with a Detroit locker. It’s a ‘1 1/4ton’ truck with a GVW of 9,450lbs.

Couple of modern touches by James. Flares cover the upsized tires nicely.

Rescue points are beefy.

Stealth mode lights for driving through the enemy lines at night. They are dim and can only be seen up close.
How did you end up with a military ambulance?
I had been scouring the classifieds for a budget trailer that I could build out and use as an all-season basecamp, when I came across an ad for the truck. It had less than 74,000 kms on the odometer and was cheaper than any of the utility trailers or campers that I had been looking at. What could go wrong?
The used car dealer who posted the ad had picked it up at a government surplus auction a few years earlier, and hadn’t really done anything with it since. It looked to me like the truck had been a giant lawn ornament to draw people onto the lot. There was a family of mice living in the coolant reservoir and the fuel system was leaking all over the place. The military had removed all of their radio and medical equipment before selling it at auction and had cut hundreds of wires, leaving a tangled mess of unidentified live wiring. The tires were rotten and cracked, the batteries weren’t charging and half the instruments on the dash didn’t work. Needless to say, I bought it on the spot.
Why is it called Rolling Thunder?
It’s big, it’s slow and it’s loud.
In university, my roommate had inherited a 90’s metallic turquoise-teal Pontiac Grand Am from his grandparents that had the nickname Rolling Thunder. We used that car to get to mountain bike races and to and from our job trail building in the summer. It broke down several times and always seemed to have a flat tire, but it got the job done. The nickname was inherited by my truck, in memoriam.

Meaty 37" BF Goodrich KOs.

The alloy wheels complement the boxy design of the truck nicely.
Why is it called Rolling Thunder? -It’s big, it’s slow and it’s loud.
How was the drive across the continent?
It was slow… and loud [see above].
The truck is geared low, with a 4.56 ring and pinion ratio and that three-speed transmission with no overdrive. It’s got the same power as a modern Toyota Corolla, at more than double the curb weight. On a flat road with a tail wind, we were barely able to hold 85 kph, making for a long couple of days crossing Ontario and the prairies. We didn’t want to push the truck too hard though. With no tachometer or temperature gauges, it’s hard to keep tabs on the engine except by monitoring the frequency of vibrations rattling through the cab.
Despite all that, Rolling Thunder hauled the two of us, our dog, and all of our belongings almost 5,000 kms across the country with no issues. We made the trip in January and it was -30 or colder in Saskatchewan, but the truck performed flawlessly (with frequent fluid checks and top-offs).
That cross-country haul was definitely our biggest trip in the truck to date. We drove through a whiteout blizzard north of the great lakes, raced trains across the prairies and crossed half a dozen mountain passes to make it all the way to the Pacific Ocean.
Run us through how it is to daily drive it.
Rolling Thunder is happiest on a winding gravel road, cruising along with the windows down; not a parking lot in sight and far from the glares of passing Tesla drivers. I’ve used it to commute around the city for work and to run errands, but it’s just not practical as a daily driver. It’s too big and has too many blind spots, making city traffic and parking very difficult.
It also draws a lot of attention. Could be the paint job.
I recently got my motorcycle license and have been getting around the city on a new-to-me 2008 Honda XR650L.

James kept alot of the military badging and signing... minus the big red cross.

Shore Power for when stationed at glamorous camp grounds.

A rolling bread box.

When aerodynamics didn't matter.

At least it's small and probably doesn't allow for a great rearview.

Fresh pipes for the Rolling Thunder. James also had to reverse the shackles for added clearance for the 37" tires.

Cab is through to the back sealed with a surprisingly non-leaky bellows. This is an 80s American interior at its finest.

Nothing flashy but surprisingly comfy chairs.

This is the extent of the air conditioning in this vehicle.


Just don't drop your change in there...
What’s on the to-do list for the big rig?
Between the truck and the camper fit-out, there’s an endless to-do list that seems to grow faster than I can check things off. I try to tackle one or two big tasks or upgrades each year, along with the regular maintenance and repairs.
I’m still dealing with mysterious, whack-a-mole type electrical issues that seem to manifest themselves in increasingly strange ways. Turn signals, dash lights and switches sometimes have a mind of their own.
The next big upgrade for the truck would be suspension. I’d like to replace the front leaf springs and add a few inches of lift so I can clear a crossover steering kit to improve the steering geometry. The rear leaf pack is rusty and coming apart, so it needs to be rebuilt or replaced as well.
In the camper box, the obvious next step would be to get some wall panels up. I’d also like to install a big window on one side of the box to let in a bit more light back there. The long-term goal would be to have a little food prep area with a sink and running water, as well as some more built-in storage.
There’s no real rush on any of this stuff, as the truck works just fine as it is.
What’s the coolest place you've taken it to?
Probably Yoho National Park in the Rockies, where we spent a night at Emerald Lake Lodge on our drive across from Ontario. We liked the spot so much, we went back and got married there.
We had a pretty memorable trip down through Washington and Oregon, with stops in Portland and Hood River. Admittedly not the most exotic destinations, but it was a great trip.
That’s a big part of the appeal of this truck for me. We can just throw some gear into the back and hit the road with very little planning. Having the truck ready to go in the driveway makes it easy to get out for a weekend or even just for a night.

Probably my favourite badge in the whole truck. Dimensions and COGs.

Air tower light descriptions.

More of the same.

There could be leaks and you can blow up.

Do not put your sandwich in the glovebox.

James sure collects a few stickers.

More stickers.

Airline to the exterior helps with airing up and down the truck tires. Also bikes.

Compressor lives under the bed, cooled with a computer fan.

James tells me there was a big exterior AC unit here that cooled the cab. He removed it and put windows in its place.

Custom shuttle racks for James.



No rig is complete without a custom name tag.

Bed, couch, dining room, workshop... you name it.

Preach...

The fridge is ready to serve some post-ride refreshments.

And she does plenty.

Coffee, bikes, beer, repeat.

Nuclear or just an air vent?

James does some trail building and maintenance. His tools are always ready to fire up.

The beast... 6.2L Diesel.

The dream of an engine bay... One you can sit or stand up in!!!

Simple is sweet. No struts to go bad here, just a spiral spring.
Tell us a little bit about your bike.
I’m riding a 2018 Cannondale Jekyll 3, but the only stock parts remaining on the bike are the front wheel and the frameset. I’ve replaced and upgraded parts as they’ve failed or worn out, slowly piecing together a more robust build for the riding here in BC.
I brought the Shimano XTR 11-speed derailleur, shifter and cassette over from my last bike. The cassette eventually needed replacement, but the XTR shifter and derailleur are still performing flawlessly after 8 years of hard use (despite several hard hits on that derailleur).
Here’s a spec for reference, not sure if you want to include any of this, but here ya go:
Frame: 2018 Cannondale Jekyll 3, 165mm travel, Size L
Fork: Fox 38 Factory 170mm
Rear Shock: RockShox Super Deluxe Coil Ultimate Remote, 230x60mm, 450lb Spring
I replaced the stock bushings at the shock mounts with an RWC needle bearing kit at the upper shock mount and a bearing mount kit from a Santa Cruz Nomad on the lower shock mount.
Front Wheel: Formula Hub, WTB Frequency Race i29 Rim, Cush Core
Rear Wheel: Industry Nine Torch Hub, DT Swiss FR560 Rim, Cush Core
Tires: Maxxis Assegai 27.5 x 2.5” WT 3C EXO
Pedals: Crank Brothers Mallet DH
Crankset: Race Face Atlas Cinch, 175mm
Chainring: Race Face Cinch Direct Mount, 30T
Chainguide: OneUp Bash Guide
Rear Derailleur/Shifter: Shimano XTR M9000 Shadow+ 11 Speed (w/ Wolf Tooth GoatLink)
Rear Cassette: Shimano XT 11 Speed 11-42t (w/ Wolf Tooth 45t cog)
Handlebar: OneUp Carbon Handlebar, 20mm rise
Grips: OneUp
Stem: OneUp EDC Stem, 35mm
I had some trouble keeping everything tight with the EDC stem preload system, so I abandoned that and went back to the threaded steerer tube. I haven’t had any issues since (looks like they’ve discontinued it).
Headset: FSA No.42 / ACB-A
Brakes: Shimano ZEE, with 203mm/180mm Shimano Ice Tech rotors
Saddle: Fabric Radius Scoop (my second one, as I bent the rails on the first)
Seatpost: OneUp Dropper, 31.6mm, 180mm drop

2018 Cannondale, 1985 Chevy

Truck has bigger wheels... by a lot.

Striking colour combo on the Cannondale.

The Ltd Ed'n Pistachio Fox 38 is a bit of a rare item.

So is the remote lockout RS Super Deluxe Coil.

The holy grail.. black Grip2 dials!

OneUp bars for precision and comfort.

Gemini lockout delete, replaced by a Commencal-sourced Super Deluxe with its own lockout lever.

By far the best brakes Shimano has made.

I9 Torch Hubs round off the package.

A Canadian Veteran and his unique projects.

James, his wife and their late dog - PC : Whistler Elopements

We dedicate this Pistons & Pivots to James' Best friend " ROCKY " - PC : Whistler Elopements
Comments
kcy4130
1 year, 11 months ago
Surplus military vehicles are very cool. Ambulances based on a 4x4 chevy truck chassis are very cool. This is cool^2. Thank you James for sharing and Merdano for the amazing photos! I love these features!
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Deniz Merdano
1 year, 11 months ago
It was a no brainer! What a unique setup hey?
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Pete Roggeman
1 year, 11 months ago
No kidding. Love these one-off conversions that break the mould.
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Vik Banerjee
1 year, 11 months ago
Yes. Anything with olive drab/camo is a great start. Should get another post in 5 years to show the upgrades/development. :-)
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mrbrett
1 year, 11 months ago
That truck is awesome! It would be so fun to build - there's a whole aftermarket for CUCV parts, and a 6.2L/TH400/D60/14b is a great combo to run indefinitely. Sounds like it's time for a wiring harness but even that would be a good chance to get all the camper-ey stuff integrated nicely.
Pretty jealous about this one, I think it's the best in the P&P series so far.
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rollingthunder.jpeg
1 year, 11 months ago
Thanks dude!
I've been trying to delay the inevitable, but I'll eventually have to strip out all the wiring and start fresh.
The camper-ey stuff has it's own deep cycle battery and stand-alone electrical distribution in the box. It's tied into the batteries up front through a charge controller that selects between the solar panels and alternator.
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Mammal
1 year, 11 months ago
Great old truck! I enjoy reading about the old stuff in these articles more than the new.
How are Zee brakes better than Saint? Am I missing (out on) something?
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Pete Roggeman
1 year, 11 months ago
I haven't owned Zees, but everyone that does swears by them: similar/same power to Saints, less $, and - I think - a more reliable lever throw.
I'll let someone else confirm or deny all that.
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Mammal
1 year, 11 months ago
Weird about the lever throw situation. Saint just has a barrel adjuster added, so I'd be interested in hearing whether there is some sort of advantage to be had without (I can't see how). I certainly love my Saints.
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Deniz Merdano
1 year, 11 months ago
Zee's were the last of the shimano high pressure brakes that had the older master cylinder architecture. Those were less susceptible to pumping up and since the calipers were the same as the Saints, they were just as powerful. Never seen a Zee get warrantied where as 1 out of 4 saint would be warrantied at the shop.
Also.. yes... ZEE is a great name...
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Mammal
1 year, 11 months ago
That makes no sense to me. The Saint and Zee levers are identical, other than the barrel adjuster and finish. The Saints levers have not been updated like the XTR/XT/SLX/Deore, but yes, the MC are identical as well.
https://bike.shimano.com/en-EU/product/component/saint-m820/BL-M820-B.html
https://bike.shimano.com/en-EU/product/component/zee-m640/BL-M640-B.html
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Velocipedestrian
1 year, 11 months ago
The MC on the Zee is the same as the SLX of that generation, the Saint is the same as the XTR - big plastic top vs machined complete.
No idea what practical difference this makes, but have wandering Saints and solid SLX in the house.
Deniz Merdano
1 year, 11 months ago
Quite different as you can see. I believe one of the reason was the placement of the bleed hole on the Zees actually being at the highest point in the MC, where as the newer shimano design has a bigger expanding bladder and not the best bleed port placement.
These are my own personal opinions backed by several shop rats...
Mammal
1 year, 11 months ago
You guys are correct, my bad. I've never heard of the WBP issue with Saints, and was also obviously convinced that the MC/levers were the same. I'm glad I've got no issues with getting a good bleed with the Saints or WBP issues that I get occasionally with the SLX I've got.
Vik Banerjee
1 year, 11 months ago
I mean just the name is a winner. The more times you get to say "Zee!!!" the better. ;-)
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BenHD
1 year, 11 months ago
Ohhh the photos again Deniz. Very easy on the eyes!
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Deniz Merdano
1 year, 11 months ago
thank you kindly!!
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Kenneth Perras
1 year, 11 months ago
Nice feature. I appreciate the less conventional vehicle choices out there, and this one fits the criteria. Side note: those KOs must be rock hard by now!
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Deniz Merdano
1 year, 11 months ago
KOs are not stock... They were a recent addition by James to both increase ground clearance and lower highway RPMs.
But I personally find the KOs to be hard in general
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Pete Roggeman
1 year, 11 months ago
Can we talk other choices that are suitable for our needs out here? Whether 4-season or 3-season+? I may know someone who's going to need a new A/T or M/T soon to gussy up Blue Thunder's successor...
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mrbrett
1 year, 11 months ago
If you watch the tread depth/load rating, Falken Wildpeak AT3Ws can be a decent contender. I have a set now and much prefer it to the KO2s I had previously. Way better on ice for sure, great in standing water on the road, ride OK aired down, seem burly enough, didn't weigh a ton to kill off fuel economy. Pricing also favours Falken over BFG.
I say watch the specs because some are more like a highway tire with shallow tread depths or low load ratings.
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Deniz Merdano
1 year, 11 months ago
Putting Wildpeak A/T trails on the Forester soon. They are way lighter and quieter than the KO2s. Will be perfect for the awd FSR hooner .
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rollingthunder.jpeg
1 year, 11 months ago
Planning to go with the Falken Wildpeak's next. I really only went with these previous generation KO's because they were on clearance when the KO2's came out. When you're getting a full set of five 37's, pricing is hard to ignore! haha
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Vik Banerjee
1 year, 11 months ago
Toyo Open Country Extreme ^^^. I've been enjoying these for daily driver use. Reasonable on pavement and still useful on gravel, dirt & snow. I want to be able to comfortably drive to Moab as well as explore a bit when I get there. So far there is no place I've wanted to take my truck where these weren't working well. But, my rig is too big/heavy for any real 4x4ing offroad.
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T-mack
1 year, 11 months ago
I bought the same and have been impressed, especially here in Kamloops this winter. I bought mine from Tirewarehouse.ca. Cheapest I could find and fast shipping, highly recommend.
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Pete Roggeman
1 year, 11 months ago
I'll be in a similar boat, since we're planning to get a camper for the back, so it's more about versatility in mixed condition than raw off-road performance.
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silverbansheebike
1 year, 11 months ago
Recently bought some Yokohama Geolandar AT G015 for my colorado, they got me across the country in January. Better than any snow tire i've had, and hardly affect my mileage on the pavement. nice and quiet too.
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JakeRedrum
1 year, 11 months ago
I have the same setup: Geolandars on a Colorado for the summer, and Halkappetta G3s -for winter (Nokians are better on the ice than the Yoko's in my experience). These Pistons and Pivots are awesome!
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mtnfriend
1 year, 11 months ago
I love the Geolanders on my lifted first gen tundra that carries my FWC Hawk around during the summer months, 10 ply, and they're great. But, for real winter driving nothing berets the Hakkapelita, that's what I run in the winter here in Revelstoke.
hairymountainbeast
1 year, 11 months ago
I've liked the maxxis razr AT's that are on my truck. Pretty good on road, really good on snow and mud and dirt. The only downside is the need to be rotated more frequently than BFG's, like every 3-5K miles.
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rollingthunder.jpeg
1 year, 11 months ago
I wouldn’t say no to a new set of ultra-sticky 37" Maxxis Trepadors... :D #presentedbyMaxxis #pistonsandpivots #nsmb
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Pete Roggeman
1 year, 11 months ago
They have some decent looking truck tires for sure. Can't get em in Canada but that just means a road trip!
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cheapondirt
1 year, 11 months ago
The Truck-lites are fantastic headlights, but James, in case you haven't experienced it yet, snow doesn't melt off them like it would with halogen bulbs. Though I have a feeling a couple extra stops to wipe snow won't faze anyone who drives a Detroit Diesel.
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rollingthunder.jpeg
1 year, 11 months ago
The truck-lite headlights have been great. They're a big improvement over the stock ones (I also added headlight relays). No issues with snow build up so far, as the lights are close to the radiator and seem to stay pretty toasty warm. We drove cross country in January and didn't have any problems.
We did have issues with the tail lights though. We didn't know at the time, but we had no taillights for most of the drive across Manitoba. I splurged on some heated JW speaker LED tail lights when we got here.
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Ddean
1 year, 11 months ago
BOOM!!!
And there it is...its about time dammit.
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Deniz Merdano
1 year, 11 months ago
I mean it had to be done.... But still keen on putting a bike rack on that GT4 for an article....
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Endurimil
1 year, 11 months ago
LOL...have driven three different versions of the CUCV back in the early 1990's. Even used the CUCV Amb as a camper while on ex. Benefits of being the driver. LOL
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